1. Field of the Invention
The present invention relates to a semiconductor memory device and a method for manufacturing the same.
2. Description of the Prior Art
Generally, the most important factor for an integration of dynamic random access memories (DRAMs) which are the memory devices having the most wide applications is to provide the charge storage capacities of memory cells.
The most important parameters for the charge storage capacities of DRAM's memory cells include surface areas of charge storage electrodes and thicknesses of dielectric films.
Conventional DRAMs comprise a memory cell circuit and a peripheral circuit with a metal oxide silicon field effect transistor (MOSFET) both formed over a semiconductor substrate. For increasing effective areas of cell capacitors, the trenched structure or the stacked structure is employed.
However, such conventional DRAMs encounter a problem of a complexity of processes due to an increase in topology and thereby a limitation on increase in topology.